Wept detector for looms



June 2, 1931. G. A. BUFFINGTON 1,807,730

WEFT DETECTOR FOR LOOKS Filed Dec. 28. 1929 A77'0FPNE Y5 Patented June 2, 1931 UNITED STATES PATENT OFFICE KNOWLES LOOM WORKS, OF WORCESTER,

MASSACHUSETTS MASSACHUSETTS, A CORPORATION OF WEFT DETECTOR FOR LOOMS Application filed. December 28, 1929. Serial No. 417,215.

This invention relates to improvements in weft detectors for looms more particu larly of the side slipping type, and it is the general object of the invention to provide an improved resilient feeler tip which will act to soften the blow on fine yarns incident to the feeling operation. I

It occasionally happens that with certaln classes of yarn a side slip feeler will cause fraying or abrading to such an extent as to mar the appearance of the finished fabric. This is likely to happen where the parts moved by the yarn have any appreclable weight which must be set 1n motion by a force transmitted through the weft surface. It is an important object of my present 1nvention to form the feeler tip of a colled wire which surrounds a guiding core to hold the Wire in yarn engaging posit on.

It is a further object of my present invention to provide a sliding guide on a feeler arm and surround said guide with a colled spring the effect of which is to hold the guide in rearward yarn engaglng position, the spring serving the dual purpose of yieldingly holding the gulde 1n operatlve posltion and also providing a detectlng surface to be embeddedin the coils of weft.

WVith these general objects in view WlllCll will appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth in the claims.

In the accompanying drawings, wherein a convenient embodiment of my invention is set forth,

Fig. 1 is a top plan view of a detector havingmy improved tip applied thereto, certain parts being removed for the salze or clearness and the parts being shown n non indicating but detecting relation wlth respect to a full bobbin,

Fig. 2 is a view simllar lJO FIgZ. 1 but w th the detector moved to indicating positlon along a substantially empty bobbin,

Fig. 3 is a vertlcal section on hne 33 of Fig. 1,

Fig. 4 is a detailed vertlcal section on llne of Fig. 1, y

Fig. 5 is a plan vlew on an enlarged scale of the detector tip, the cover being removed to set forth the interior structure of the guide holder, and

Fig. 6 is a vertical section on line 6-6 of Fig. 5.

Referring to the drawings, I have shown a stand 10 having an upstanding horn 11 provided with a slot 12 through which vertically reciprocates one end of an actuator lever 13. A controller 14 is pivoted as at 15 to a portion of the stand and is normally out of the path of the actuator, but is movable thereunder to interrupt the downward movement thereof and effect a change in the operation of the loom, as described in prior Patent No. 1,030,748.

The detector comprises a base or bed 16 and cover 17 having aligning slots 18 through which extends a securing bolt 19. The latter is held to the stand 10 and in this way supports the bed and cap in fixed position. A slide member 20 is mounted for reciprocating movement between the bed and cap and has an upstanding end 21 which serves to limit rearward movement of the slide and also afford means for the read withdrawal of the slide at the time of transfer.

A detector arm 22 is pivoted as at 23 to the slide and has a forwardly extending finger 24 which is limited as to angular movement in one direction by a stop pin 25 on the slide 20. The fingeris positioned. for engagement with the controller 14 at the time of indication of weft exhaustion.

The arm is engaged at one side of the pivot pin 23 by a compression spring 26 the forward end of which pushes against the fixed bed and the rear end ofwhich acts on the detector in a manner set forth in Patent No. 1,738,198 to hold the detector arm in normal angular position and also move said arm together with its supporting slide rear- Wardly after each non-indicating detecting action. The detector arm extends rearwardly as at 27. The matter thus far described is of common construction and may operate substantially as set forth in the aforesaid patents.

In carrying my invention into effect I proslots 43 formed in the plates, the plates and arm being thus held rigid with respect to each other.

As shown in Fig. 5 the lower plate is provided with right and left hanc grooves 44 and 45, respectively. through which slide the parallel legs 46 and 47 of a core or guide member 48. The core is sim larly formed and holds the member 48 in position. The sliding core is formed of a single piece of wire, the rear portion of which is rounded as at 49 and one of the legs of which, namely 47 in this instance, is bent laterally at 50. The bent end engages a shoulder 51 formed on the lower plate to limit rearward movement of the guide.

A coiled compression spring 52 surrounds the guidev and has the forward ends thereof in abutment with the rear walls 58 of the top and bottom plates. The effect of the spring is to hold the bent end 50 yieldingly against the shoulder 51, permitting forward motion of the guide with respect to the detector arm and plates supported thereby.

In addition to holding the guide rearwardly, the wire spring .also provides the detecting surface and with this in mind I contemplate making the spring of such size as will be best adapted to the particular yarn being detected.

In operation the principal spring 26 will hold the slide and detector in rearward position and the spring 51 will be expanded as much as possible with the bent end 50 against the shoulder 51. As the bobbin B carried by the shuttle S moves forwardly the weft IV will engage the rearmost coils of the spring 52. When sufficient weft is present the coils of the spring will be embedded in the yarn sufficiently to prevent side slipping. Upon continued forward movement of the bobbin the spring 52 will be. compressed inasmuch as it is weaker than the spring 26. During this forward advance, however, the compression spring 26 will eventually be moved forwardly, but not until after the initial contact between weft and detector.

As the lay advances on indicating beats of.

' the loom thespring 52 will slide along the bare bobbinto assume a position such as thatshowirin Fig, 2. Under these circumstances the finger 24 will engage the controller 14 to move the same to the dotted line position shown in Fig. 4 under the actuator lever to interruptdownward movement of the latter and thereby effect a change in the operation of the loom.

From the foregoing it will be seen that I have provided a simple detector tip having a stiff guiding core surrounded by a helical spring which performs two functions, namely, holding the guide or core and itself yieldingly in rear normal position, and serving as the detecting or yarn engaging surface. The weight of the guide 46 or core together with the spring is less than the weight of the slide 20 and the detector arm and it is this light weight which is set into motion by the initial contactof the weft with the detecting surface. Furthermore, it will be seen that when the spring 52 is made sufficiently light to permit easy yielding it requires some form of support to be held in proper yarn engaging position, and this support not only prevents distortion of the spring but also slides through the ends of the spring so as to effectively reduce the length of the spring and thereby bring about a slight motion on the part of the spring coils with regard to the yarn to assist the coils to embed themselves into the weft. In other words, the act of detection causes a slight crowding together of the spring coils relatively to the weft yarn coils.

Having thus described my invention it will be apparent that changes and modifications may bemade therein by those skilled in the art without departing from the spirit and scope of the invention and I do not wish to be limited to the details herein disclosed, but what I claim is:

1. In a feeler tip for a loom weft detector arm, a support on the arm, a U-shaped wire slidably mounted on the support and limited as to rearward movement, and a coiled spring around the wire holding the latter yieldingly in rear position and having the coils thereof disposed to engage the weft to be detected.

2. In a feeler tipfor a loom weft detector arm, a housingcarried by the arm, a guide slidably mounted in the housing and having a rearwardly projecting position, and a coiled spring around the projecting position holding the same yieldingly in rear position and having the coils thereof disposed to engage the weft to bedetected.

3. In a feeler tip for a loom weft detector arm, a guide member supported-by and slidably mounted on the arm, and a coiled spring surrounding a portion of the guide to be supported thereby and hold said guide yieldingly in rear position, the spring coils being disposed to engage the surface of the weft to be detected.

4. In a feeler tip for a loom weft detector arm, a guide supported by and slidable on the arm and having a subStantially-U shaped rearward extension, and a spring coiled around the extension and holding the lat- 

